I tryed to access GPIO1 to 8 from Apalis T30 (+ Ixora Carrier Board) with some C-Code. These GPIOs are available by Extension Header X27. Unfortunately GPIO7 cannot be set by the program.
I extended the gpio_output example .c and .h files. GPIO7 was defined this way:
#define GPIO_07_VALUE "/sys/class/gpio/gpio151/value" //S07 Tegra #define GPIO_07_DIRECTION "/sys/class/gpio/gpio151/direction"
If I try to access via terminal window I get “No such file or directory”. The export command also did not work.
echo 151 > /sys/class/gpio/export
I get “echo: write error: Device or resource busy”. Unexport says “echo: write error: Invalid argument.” When 189 is used like the GPIO (Linux) example it is possible to export/unexport.
What I’m doing wrong?
Another question is, how to read the GPIO value correctly if it’s an input?